perf tools: Long option completion support for each subcommands

Add internal --list-opts option to print all of long option names to
stdout so that it can be used for bash completion engine.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1349191294-6926-4-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/bash_completion

@@ -33,8 +33,13 @@ _perf()
 		fi
 	# List possible events for -e option
 	elif [[ $prev == "-e" && "${COMP_WORDS[1]}" == @(record|stat|top) ]]; then
-		cmds=$($cmd list --raw-dump)
-		COMPREPLY=( $( compgen -W '$cmds' -- "$cur" ) )
+		evts=$($cmd list --raw-dump)
+		COMPREPLY=( $( compgen -W '$evts' -- "$cur" ) )
+	# List long option names
+	elif [[ $cur == --* ]];  then
+		subcmd=${COMP_WORDS[1]}
+		opts=$($cmd $subcmd --list-opts)
+		COMPREPLY=( $( compgen -W '$opts' -- "$cur" ) )
 	# Fall down to list regular files
 	else
 		_filedir

tools/perf/util/parse-options.c

@@ -384,6 +384,8 @@ int parse_options_step(struct parse_opt_ctx_t *ctx,
 			return usage_with_options_internal(usagestr, options, 1);
 		if (internal_help && !strcmp(arg + 2, "help"))
 			return parse_options_usage(usagestr, options);
+		if (!strcmp(arg + 2, "list-opts"))
+			return PARSE_OPT_LIST;
 		switch (parse_long_opt(ctx, arg + 2, options)) {
 		case -1:
 			return parse_options_usage(usagestr, options);
@@ -422,6 +424,12 @@ int parse_options(int argc, const char **argv, const struct option *options,
 		exit(129);
 	case PARSE_OPT_DONE:
 		break;
+	case PARSE_OPT_LIST:
+		while (options->type != OPTION_END) {
+			printf("--%s ", options->long_name);
+			options++;
+		}
+		exit(130);
 	default: /* PARSE_OPT_UNKNOWN */
 		if (ctx.argv[0][1] == '-') {
 			error("unknown option `%s'", ctx.argv[0] + 2);

tools/perf/util/parse-options.h

@@ -140,6 +140,7 @@ extern NORETURN void usage_with_options(const char * const *usagestr,
 enum {
 	PARSE_OPT_HELP = -1,
 	PARSE_OPT_DONE,
+	PARSE_OPT_LIST,
 	PARSE_OPT_UNKNOWN,
 };